Seasonal Depression Overview

Seasonal affective disorder (SAD) is a type of depression that is tied to seasons of the year. Historical facts about SAD include that as early as 400 BC, Hippocrates described changes in seasons as causing illness. Two hundred years later, light therapy was being recommended as treatment for people described as "lethargics" or suffering from "gloom." Most people with SAD are depressed only during the late fall and winter (sometimes called the "winter blues") and not during the spring or summer. That many cultures celebrate a number of holidays during the winter can be an additional stress for people with SAD. A small number of SAD sufferers, however, are depressed only during the late spring and summer. In contrast to SAD, other forms of recurrent depression, like bipolar or unipolar depression, occur independently of the time of year.

SAD is most common in young adult women, although it can affect men or women of any age. SAD affects people in both hemispheres an rarely within 30 degrees latitude of the equator. Some people may have a milder form of seasonal mood change.

Like all types of clinical depression, SAD can have a devastating effect on a person's life. Fortunately, almost all people with SAD can be helped with available therapies.